Pathological Spontaneous Activity in Different Thoracic Paraspinal Muscles in Amyotrophic Lateral Sclerosis

Objective: The aim of our study was to compare the clinical value of pathological spontaneous activity (PSA) in different thoracic paraspinal muscles (TPMs) in amyotrophic lateral sclerosis (ALS).

Methods: A total of 116 ALS patients were retrospectively analyzed over 31 ± 8 months concerning the occurrence of PSA in T9–T11 TPM. The occurrence of PSA was correlated with pulmonary function and clinical disability.

Results: The positive sharp wave (PSW) potentials were more frequently observed than fibrillation (fib) in T9–T11 segments. The PSA positive frequency of bulbar-onset ALS (B-ALS) is less than upper limb-onset ALS (U-ALS) and lower limb-onset ALS (L-ALS) at the levels of T10 and T11 TPM (p = 0.050, p = 0.001). The fibs/PSWs in TPM indicated high sensitivity and negative predictive value for forced vital capacity (FVC) < 80%. Linear correlation analysis indicated that PSA of TPM was associated with pulmonary ventilation function (PVF). Associations also exist between clinical parameters and PVF as well as the disease severity.

Conclusions: The occurrence of T9-TPM fibs/PSWs was correlated with clinical disability and is extremely helpful in implying an involvement of PVF. The T9-TPM typically provided a good practical indicator for comprehensive disease evaluation, which was irrelevant to the site of onset.